Air diffuser

ABSTRACT

Wall means define a generally elongated, narrow air passage having an air discharge aperture extending substantially the full length of the elongated air passage and an air inlet located generally centrally of the elongated dimension of the air passage. A baffle or air deflecting means, disposed within the air passage opposite the mouth of the air inlet, is shaped so as to direct air entering the air passage in both directions along the elongated dimension of the air passage. Preferably the diffuser is equipped with adjustable shutter means mounted within the air passage and engageable with the air inlet so as to control the volume of air moving into the air passage from the air supply.

PTENTEDJUL 4 |972 3,673,946

Douglas Ragland /NVENTOR 22 ATTORNEY United States Patent Ragland [54]AIR DIFFUSER [72] Inventor: Douglas Ragland, Houston, Tex.

[73] Assignee: Texas Investment Builders Co., Houston,

Tex.

[22] Filed: March 25, 1970 [21] Appl. No.: 22,490

[52] U.S. Cl. ..98/40 D, 138/37, 137/606, l 239/598 [51] Int. Cl. F24f13/06 [58] Field of Search ..98/40 DL, 40 C, 41; 138/39, 138/37 X;239/503, 502, 598 X; 137/606 X [56] References Cited UNITED STATESPATENTS 3,260,188 7/ 1966 Person ..98/40 D 2,771,833 11/1956 Halliday etal. ....98/40 C 1,300,380 4/ 1919 Griffin ..138/37 2,814,243 1 l 1957Berger et al... ..98/40 C 3,348,465 10/ 1967 Kruger ..98/40 DL [45] July4,1972

3,343,473 9/1967 Gillick et al. 9S/l0 FOREIGN PATENTS OR APPLICATIONS507,683 l l/l954 Canada ..98/40 C Primary Examiner-William E. WaynerAttorney-Ralph R. Browning [5 7] ABSTRACT Wall means define a generallyelongated, narrow air passage having an air discharge aperture extendingsubstantially the full length of the elongated air passage and an airinlet located generally centrally of the elongated dimension of the airpassage. A baffle or air detlecting means, disposed within the airpassage opposite the mouth of the air inlet, is shaped so as to directair entering the air passage in both directions along the elongateddimension of the air passage. Preferably the diffuser is equipped withadjustable shutter means mounted within the air passage and engageablewith the air inlet so as to control the volume of air moving into theair passage from the air supply.

8 Claims, 7 Drawing Figures BACKGROUND OF THE INVENTION The presentinvention relates to air diffusers and more particularly to air difusersfor use with light troffers and perimeter air induction systems.

It has become accepted practice in the commercial building industry tointegrate overhead air handling and lighting systems into a single unit.The use of such integrated systems provides an aesthetically pleasingappearance inasmuch as it reduces the number of outlets and fixtures inthe ceiling. Another advantage realized from such systems is the reducedcost of installation since only a single opening need be cut in theceiling for the combined light-air unit.

The use of these integrated air handling treffers, as they are commonlyknown, does pose some problems. One of the problems in the use of suchintegrated systems is that they are normally installed in commercialbuildings wherein false or drop ceilings are employed. ln such ceilings,of course the space available in the areas both above and on the sidesof the fixture is limited. The design of an eicient air diffuserpresents certain difficulties which, to mention a few, include ensuringthat an adequate supply of air enters the air passage, providing meansto permit convenient adjustment of the air flow being discharged fromthe air passage and ensuring that unwanted drafts are not allowed whichwould cause discomfort to the occupants of the room. It is thereforeclear that the design of the plenum chamber or air passage is quitecritical, it being desirable that the plenum chamber fit as snugly aspossible onto the chassis of the trofi'er and still be an efficient airdistributor.

SUMMARY OF THE INVENTION It is therefore an object of the presentinvention to provide an improved air diffuser for use with a lighttroffer.

Another object of the present invention is to provide an improved airdiffuser for use with a light troter in which the volume of air flowinto the unit can be easily adjusted.

YetA another object of the present invention is to provide an airdiffuser for use with a light troffer which provides improveddistribution of air flow.

Still another object of the present invention is to provide an improvedair diffuser for use with a light troffer in which the direction of airflow exiting from the diffuser can be readily adjusted.

Another object of the present invention is to provide an `air diffuserfor use in a perimeter air induction system.

These and other objects, advantages and features which will becomeapparent from the attached drawings, the description given herein andthe appended claims are provided by the present invention.

The air diffuser herein comprises a suitable wall means which defines anelongated, generally narrow air passage. Located centrally of theelongated dimension of the elongated air passage is an air inlet throughwhich incoming air passes. An elongated air discharge aperture extendssubstantially the full length of the elongated air passage. A baffle orair deflecting means is so disposed within the air passage and has ashape such that air entering the air passage and impinging upon thebaffle is directed longitudinally towards the ends of the air passage.Preferably, an adjustable shutter means is mounted within the airpassage. The shutter means, which is engageable with the air inlet,serves to control the volume of air entering the air passage.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an isometric view of the airdiffuser of the present invention.

FIG. 2 is a cross-sectional View taken along the line 2-2 of FIG. l.

FIG. 3a is a cross-sectional view taken along the line 3-3 of FIG. 2.

FIG. 3b is a view similar to FIG. 3a showing another form of baffle.

FIG. 4 is a cross-sectional view taken along the line 4-4 of FIG. 2.

FIG. 5 is a view similar to FIG. 4 showing a modification of the airpassage design of the air diffuser.

FIG. 6 is an enlarged isometric view of the baffle shown in FIG. 3b.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the Figures,the air diffuser is seen to comprise an elongated stepped side wall 10,an elongated, substantially flat side wall 1l (best seen in FIG. 3a), apair of end walls l2 and 13, respectively, and an elongated top wall 14.While end walls 12 and 13 are shown as having a lower substantiallyvertical section and an upper inwardly inclined section, walls 12 and 13can of course be planar, outwardly inclined, concave, etc. Stepped sidewall 10 is comprised of an upper vertical section l5, a lower verticalsection 16 and a laterally extending section or shelf 17, the oppositeedges of which are connected to upper and lower vertical sections 15 and16, respectively. Walls 10, 11, 12, 13 and 14 define a generallyelongated, narrow air passage 18. A circular air inlet 19 is locatedgenerally centrally of the ends of stepped wall l0 and communicates withair passage 18. A collar 20 extending from stepped side wall 10 allowsan air supply conduit 21 (shown in phantom lines) to be easily connectedto the air diffuser. Lower vertical section 16, together with thelowermost portions of walls 1l, 12 and 13 serve to define an elongatedair discharge aperture 22 which extends substantially the full length ofthe air diffuser. As best seen in FIGS. 1 and 4, lower vertical section16 and the lowermost portion of side wall 11 have inwardly extendingflange portions 23 and 24, respectively which serve to constrict themouth of the air discharge aperture 22.

Mounted within air passage 18 is a V-shaped baffle 25 having inclinedlegs 26 and 27 joined together at an apex 28. Baffle 25 is securedwithin air passage 18 by means of flanges 29 and 30 extending from thefree ends of legs 26 and 27, flanges 29 and 30 being secured to wall 11by welding or some other suitable means of fastening. As seenparticularly in FIG. 3a, balile 25 is mounted within air passage 18 suchthat the apex 28 is in close proximity to air inlet 19. Thus when airpassing via inlet 19 into air passage 18 impinges upon the inclined legs26 and 27 of bale 25, it is diverted toward respective ends of thepassage 18, i.e., towards end walls 12and 13, respectively. Flow arrowsin FIG. 3a clearly depict the air flow pattern described above.

Also disposed within air passage 18 are adjustable shutters 31 and 32which are engageable with air inlet 19. A bolt 33 extends through a slot34 in vertical section l5 of stepped wall 10 and screws into a threadedhole in shutter 31. A spring 35 biased between the head of bolt 33 and awasher 36 resiliently urges shutter 31 against the inside surface ofupper vertical section 15 of stepped wall 10. By adjusting screw 33, thefrictional contact between shutter 31 and vertical section 15 can beincreased or decreased as desired. By like means, shutter 32 is slidablymounted within air passage 18, bolt 37 extending through slot 38 andspring 39 being biased between the head of bolt 37 and washer 40. Toslide either shutter 31 or 32 so as to increase or decrease the volumeof air entering passage 18, it is only necessary to insert a rod or thelike through air discharge aperture 22 and move the shutter in thedesired direction. Thus it is seen that the volume of air entering theroom being ventilated can easily be controlled from below the ceilingwith relative ease. Although not necessary, generally each of shutters3l and 32 will be disposed so as to engage approximately one-half of thearea of inlet 19 whereby if both shutters 31 and 32 are moved to aclosed position, i.e., towards one another, substantially no air willenter air passage 18 through inlet 19. Also, as will be readilyrecognized, the unique dual shutter system provided herein allows oneside of the air diuser to be shutoff while the other side is atsubstantially full volume. It is to be understood that the method ofslidably mounting shutters 31 and 32 in air passage 18 is merely oneillustration of numerous methods that can be utilized. It is onlynecessary that shutters 31 and 32 be adjustable so that the volume ofair entering passage 18 be controllable.

Shutters 31 and 32 are also provided with deector plates 41 and 42respectively. Deflector plates 4l and 42 which may be integral withshutters 31 and 32 or separate parts fastened thereto by some suitablemeans serve to divert air moving through air passage 18 in a generallydownwardly direction towards air discharge aperture 22. Naturally theexact design of deflectors 41 and 42 can vary depending on the airdistribution sought. For example, deflectors 4l and 42 can besubstantially the same width as air chamber 18 as determined by thedistance between walls l1 and l5 or as shown in the drawings, can beless than the width of air chamber 18 between wall 11 and l5.Furthermore, it is not necessary that deilectors 41 and 42 be employedat all.

As best seen in FIGS. 4 and 5, the air diiuser is equipped with an airdischarge pattern control means comprising a vane plate 43 which extendssubstantially the full length of air passage 18. Vane plate 43 is ashallow generally V-shaped member having legs of unequal length, theshortest leg of vane plate 43 being secured to the inside surface ofvertical section 16 of stepped wall l0, the longer leg of vane plate 43extending into air passage 18 such that air leaving air passage 18 andstriking the inwardly facing surface will be directed toward the lowerpart of side wall 11 adjacent air discharge aperture 22. Thus, air whichpasses through air discharge aperture 22 is diverted laterally outwardby its impingement upon the upper surface of flange 24 at air dischargeaperture 22. As is seen in FIG. 4 in the phantom lines, vane 43 may bepositioned on either of side walls l or 1 1 depending on which directionit is desired to laterally divert the air flow. While vane 43 is shownas a rigid member, it can be a hinged member which can be continuouslyadjusted from a full vertical position, i.e., forming no impediment toair flow through air discharge aperture 22, or to a position such asshown in FIG. 4 where considerable diversion of the air flow out of airdischarge aperture 22 is accomplished. Lastly, as will be apparent, vane43 may be dispensed with entirely if it is desired to allow directvertical flow of the air out of air discharge aperture 22. Nonetheless,the use of vane plate 43 or some such similar device provides an easymeans of predirecting the air flow out of aperture 22.

As should also be noted in conjunction with the use of the vane 43,flanges 23 and 24 may be dispensed with if desired, it being preferredthat at least one be used when vein 43 is ernployed so as to allowlateral diversion of the air flow as it exits through air dischargeaperture 22. The position of vane plate 43 determines which of flanges23 or 24 is needed. If vane plate 43 is attached as shown in FIG. 4,flange 24 is used whereas if vane plate 43 is attached as shown in thephantom lines in FIG. 4, flange 23 is needed.

In FIGS. 3b and 6, a modied form of baffle is shown. Baffle 44 issubstantially V-shaped on one end having inclined legs 45 and 46attached to flange portions 47 and 48. Flange portions 47 and 48 furnisha means to secure bale 44 to wall 1l of the air diffuser. As best seenin FIG. 6, bale 44 tapers from one end to the other such that it isV-shaped on one end as explained above, substantially flat at theopposing end and substantially trapezoidal in shape having a flat top 49when viewed in transverse cross-section intermediate ofthe substantiallyflat end and the V-shaped end. As will be apparent from a comparison ofbales 25 and 44, the use of bale 44 does not result in all of the airbeing divided and diverted towards opposite ends of air passage 18 asdoes the use of baffle 25. Nonetheless, baffle 44 does serve to divertat least a portion of the incoming air to respective ends of the airpassage 18. In general, the precise shape of the baffle means is notcritical provided it is shaped so that at least a portion of the airentering air chamber 18 is diverted towards the respective ends of airchamber 18. Thus, for example, the baffle could be a channel-shapedmember having a flat-top surface adjacent the air inlet and outwardlysloping legs which were fastened to the other side wall of the airdiffuser. Such a bale would have a trapezoidal-shape when viewed intransverse cross-section. Likewise, the bale could have an arcuate,oval, circular or other such shaped surface, the only requirement beingthat the bale serves to distribute the air towards respective ends ofthe air passage.

As will be evident from the foregoing, while the air passage formed bythe wall means will be generally of an elongated and narrow shape, itsprecise shape is not critical. For this reason, various combinations ofwall means can be employed depending on the desired configuration of theair passage sought. FIG. 5 shows one modification of the air diffuserherein wherein side walls 50 and 5l are substantially flat beingconnected at their upper edges to top wall 52. In the modification ofthe air diluser shown in FIG. 5, deflector 53 is not rectangular as isdeflector 4l but has a generally trapezoidalshape to accommodate thegenerally trapezoidal cross-section of air chamber 18 formed by walls50, 51 and 52. Whatever the precise cross-sectional shape of air passage18, it is preferable that the width of air passage 18 as determined bythe distance between the elongated side walls be greater at the top,i.e., closest the air inlet, than at the bottom, i.e., closest the airdischarge aperture.

While as shown above, air inlet 19 is a generally circular opening inone of the side walls, it is not necessary that the inlet be circular.Air inlet can be oval, square, triangular or virtually any other shapewhich is desired. As a practical matter, the use of a circular openingprovided with an annular collar makes for a convenient means forattaching an air supply conduit to the air diiuser. Although inlet 19 isshown as being in one of the side walls, it can be in the top wall ifdesired so long as it is located somewhat centrally of the elongateddimension ofthe air passage.

As shown above, the air diffuser makes use of dual adjustable shuttermeans mounted within the air chamber. It is to be understood however,that the use of a single adjustable shutter is within the scope of thepresent invention. Such a single adjustable shutter could be mounted oneither side of the air inlet and would serve to control the volume ofair entering one side of the air diffuser rather than having the volumecontrolled on both sides of the diffuser as when two adjustable shuttersare employed. Here again, it is not necessary that the air diffuser beprovided with any adjustable shutter means if it is desired to have axed volume of air entering the diffuser through the air inlet at alltimes.

While the air diffuser of the present invention has been described withparticular reference to its use with a light troler, it is to beunderstood that the adaptability of the air diffuser is not so limited.For example, as stated earlier, the air diffuser is ideally suited forincorporation into perimeter air induction systems. ln newer commercialbuildings, the ceiling construction generally consists of horizontallydisposed members which support ceiling panels and the lighting fixturesand air conditioning such as the air handling light troffers describedabove. In such ceiling designs, it is the normal practice to install aperimeter member which, runs along the edge of the ceiling adjacent awall. These perimeter members when properly designed having aperturestherein can be used as a grid for an air conditioning outlet. Bydischarging air into the room or building immediately adjacent anoutside wall carrying window, it is possible to neutralize the effect ofthe radiated heat at its source. However, in order to use such aperimeter air induction system, it is necessary that the air diffuser beof a design such that it ts in the quite limited space above the member.The air diffuser described above is welladapted to such an installationbeing both compact enough to fit conveniently and yet be an efficientair distributor means.

Iclaim:

1. An air diffuser comprising wall means defining an elongated airpassage, said wall means including a first elongated side wall, a secondelongated side wall, an elongated top wall, a first end wall and asecond end wall, lowermost sections of said side walls defining anelongated air discharge aperture, said elongated air discharge aperturerunning substantially the full length of the elongated dimension of saidair passage, said air passage between said side walls adjacent said airdischarge aperture being less than the `width of said air passagebetween said side walls adjacent said top wall, said air passage havingan air inlet located in said first side wall generally centrally of theelongated dimension of said elongated air passage such that air suppliedto said diffuser is fed directly into said air passage,

bale means disposed substantially wholly within said air passage, saidbaffle means being mounted on said second side wall and disposedgenerally opposite said air inlet, said baffle means having a shape suchthat at least a portion of the air entering said air passage andimpinging on said baffle means is directed longitudinally towardsrespective ends of said air passage,

adjustable, sliding shutter means mounted within said air passage, saidshutter means being engageable with said air inlet whereby the volume ofair entering said air passage may be controlled,

air discharge pattern control means disposed in said air passageadjacent said air discharge aperture whereby air exiting through saidair discharge aperture may be predirected.

2, The air diffuser of claim 1 wherein there are two adjustable shuttermeans, said shutter means being mounted on op posite sides of said airinlet, each of said shutter means being engageable with generally onehalf of said air inlet.

3. The air diffuser of claim l wherein said adjustable shutter meansincludes air deflector means for directing air moving through said airpassage towards said air discharge aperture.

4. The air diffuser of claim l wherein said rst side wall is stepped andsaid second side wall is substantially flat, said stepped side wallbeing defined by an upper vertical section, a lower vertical section anda substantially laterally extending shelf, the opposite lateral edges ofwhich are connected to said upper and lower vertical sections, saidlower vertical section of said stepped wall, the lower portions of saidend walls and the lower portion of said second side wall defining saidair discharge aperture.

5. The air diluser of claim l wherein said first side wall issubstantially at and said second side wall is substantially flat.

6. The air diuser of claim 4 wherein said air discharge pattern controlmeans is attached to one of said side walls and the lower edge of theother side wall adjacent said air discharge aperture has an inwardlyextending flange serving to constrict the mouth of said air dischargeaperture.

7. The air diffuser of claim 5 wherein said air discharge patterncontrol means is attached to one of said side walls and the lower edgeof the other side wall adjacent said air discharge aperture has aninwardly extending flange serving to constrict the mouth of said airdischarge aperture.

8. The air diffuser of claim 1 wherein said baffle means comprises aV-shaped member, Said V-shaped member being mounted in said air passageon said second side wall such that the apex of said V-shaped memberfaces and closely approaches said air inlet, the apex of said V-shapedmember being aligned generally centrally with said air inlet, theinclined legs of said V-shaped member serving to deect air entering saidair passage toward said end walls.

lk Ik

1. An air diffuser comprising wall means defining an elongated airpassage, said wall means including a first elongated side wall, a secondelongated side wall, an elongated top wall, a first end wall and asecond end wall, lowermost sections of said side walls defining anelongated air discharge aperture, said elongated air discharge aperturerunning substantially the full length of the elongated dimension of saidair passage, said air passage between said side walls adjacent said airdischarge aperture being less than the width of said air passage betweensaid side walls adjacent said top wall, said air passage having an airinlet located in said first side wall generally centrally of theelongated dimension of said elongated air passage such that air suppliedto said diffuser is fed directly into said air passage, baffle meansdisposed substantially wholly within said air passage, said baffle meansbeing mounted on said second side wall and disposed generally oppositesaid air inlet, said baffle means having a shape such that at least aportion of the air entering said air passage and impinging on saidbaffle means is directed longitudinally towards respective ends of saidair passage, adjustable, sliding shutter means mounted within said airpassage, said shutter means being engageable with said air inlet wherebythe volume of air entering said air passage may be controlled, airdischarge pattern control means disposed in said air passage adjacentsaid air discharge aperture whereby air exiting through said airdischarge aperture may be pre-directed.
 2. The air diffuser of claim 1wherein there are two adjustable shutter means, said shutter means beingmounted on opposite sides of said air inlet, each of said shutter meansbeing engageable with generally one half of said air inlet.
 3. The airdiffuser of claim 1 wherein said adjustable shutter means includes airdeflector means for directing air moving through said air passagetowards said air discharge aperture.
 4. The air diffuser of claim 1wherein said first side wall is stepped and said second side wall isSubstantially flat, said stepped side wall being defined by an uppervertical section, a lower vertical section and a substantially laterallyextending shelf, the opposite lateral edges of which are connected tosaid upper and lower vertical sections, said lower vertical section ofsaid stepped wall, the lower portions of said end walls and the lowerportion of said second side wall defining said air discharge aperture.5. The air diffuser of claim 1 wherein said first side wall issubstantially flat and said second side wall is substantially flat. 6.The air diffuser of claim 4 wherein said air discharge pattern controlmeans is attached to one of said side walls and the lower edge of theother side wall adjacent said air discharge aperture has an inwardlyextending flange serving to constrict the mouth of said air dischargeaperture.
 7. The air diffuser of claim 5 wherein said air dischargepattern control means is attached to one of said side walls and thelower edge of the other side wall adjacent said air discharge aperturehas an inwardly extending flange serving to constrict the mouth of saidair discharge aperture.
 8. The air diffuser of claim 1 wherein saidbaffle means comprises a V-shaped member, said V-shaped member beingmounted in said air passage on said second side wall such that the apexof said V-shaped member faces and closely approaches said air inlet, theapex of said V-shaped member being aligned generally centrally with saidair inlet, the inclined legs of said V-shaped member serving to deflectair entering said air passage toward said end walls.